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Foundations

Negative numbers

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Intro to negative numbers
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Number opposites
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Number opposites
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Adding numbers with different signs
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Adding & subtracting negative numbers
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Subtracting a negative = adding a positive
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Multiplying positive & negative numbers
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Why a negative times a negative is a positive
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Why a negative times a negative makes sense
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Dividing positive and negative numbers
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Practice
Negative numbers on the number lineGet 5 of 7 questions to level up!
Adding negative numbersGet 5 of 7 questions to level up!
Subtracting negative numbersGet 5 of 7 questions to level up!
Multiplying negative numbersGet 3 of 4 questions to level up!

Absolute value

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Absolute value examples
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Intro to absolute value
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Absolute value and number lines
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Interpreting absolute value
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Practice
Finding absolute valuesGet 5 of 7 questions to level up!
Interpreting absolute valueGet 3 of 4 questions to level up!

Exponents

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Intro to exponents
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Exponent example 1
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Exponent example 2
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Squaring numbers
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Intro to exponents
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The 0 & 1st power
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Powers of zero
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1 and -1 to different powers
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Comparing exponent expressions
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Exponents of decimals
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Evaluating exponent expressions with variables
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Exponents review
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Practice
Exponents (basic)Get 5 of 7 questions to level up!
ExponentsGet 5 of 7 questions to level up!
Variable expressions with exponentsGet 3 of 4 questions to level up!

Square roots

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Intro to square roots
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Square roots of perfect squares
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Simplifying square roots
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Simplifying square roots of fractions
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Simplifying square-root expressions: no variables
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Practice
Square rootsGet 5 of 7 questions to level up!
Simplify square rootsGet 3 of 4 questions to level up!
Simplify square roots (variables)Get 3 of 4 questions to level up!

Order of operations

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Intro to order of operations
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Order of operations examples: exponents
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Worked example: Order of operations (PEMDAS)
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Order of operations example
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Practice
Order of operationsGet 5 of 7 questions to level up!
Order of operations with negative numbersGet 5 of 7 questions to level up!

Fractions

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Adding fractions word problem: paint
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Adding fractions with different signs
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Multiplying positive and negative fractions
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Dividing negative fractions
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Practice
Adding & subtracting negative fractionsGet 5 of 7 questions to level up!
Multiplying positive and negative fractionsGet 3 of 4 questions to level up!
Dividing positive and negative fractionsGet 3 of 4 questions to level up!

Decimals, fractions and percentages

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Worked example: Converting a fraction (7/8) to a decimal
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Fraction to decimal with rounding
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Rewriting decimals as fractions: 0.36
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Converting decimals to fractions 2 (ex 1)
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Finding a percent
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Percent of a whole number
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Percent word problem: guavas
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Percent word problem: recycling cans
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Practice
Intro to percentsGet 5 of 7 questions to level up!
Percents from fraction modelsGet 3 of 4 questions to level up!
Relate fractions, decimals, and percentsGet 3 of 4 questions to level up!
Converting fractions to decimalsGet 3 of 4 questions to level up!
Write decimals as fractionsGet 5 of 7 questions to level up!
Finding percentsGet 5 of 7 questions to level up!
Percent word problemsGet 5 of 7 questions to level up!

Operations with decimals

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Adding decimals: 9.087+15.31
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Adding decimals: 0.822+5.65
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Subtracting decimals: 9.57-8.09
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Subtracting decimals: 39.1 - 0.794
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Multiplying decimals example
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Multiplying challenging decimals
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Dividing decimals with hundredths
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Dividing by a multi-digit decimal
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Practice
Adding decimals: thousandthsGet 5 of 7 questions to level up!
Subtracting decimals: thousandthsGet 5 of 7 questions to level up!
Multiplying decimals like 2.45x3.6 (standard algorithm)Get 5 of 7 questions to level up!
Dividing decimals: hundredthsGet 3 of 4 questions to level up!

Area of triangles

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Area of a triangle
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Area of triangles
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Practice
Area of trianglesGet 5 of 7 questions to level up!

Circumference and area of circles

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Radius, diameter, circumference & π
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Labeling parts of a circle
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Radius, diameter, & circumference
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Area of a circle
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Practice
Radius and diameterGet 5 of 7 questions to level up!
Area of a circleGet 5 of 7 questions to level up!

About this unit

This topic isn't algebra, but it is a survey of all of the most important pre-algebra skills you need to really digest algebra. These skills also tend to be pretty important in life in general!